oracle11g - Oracle: performance about filtering results from remote view -
I have a remote database that has a view v_myview. I am working on a local database, Usage is done to access v_myview on the database A. If I ask it like this: choose * v_myview to @ dblink; This gives half a million lines, I just want to get some specific rows from the view, e.g., to get the lines with id = 123, my query select v_myview @ dblink where id = 123; This question comes to me when I run this query, then the remote database will generate the first half-million lines, before id = 123 To find the rows together? Or remote visualization is applied to your filter first, then the first question to DB is to retrieve half a million lines without first? How do I know that. Thanks! Oracle is free to do either. You will need to see the query plan to see if filtering is done locally or remotely. Probably, in any case you are presenting, the adapter expects that it will be more to send the filter to the remote server rather than filtering only five lakh lines local...